Solar simulators are used in a wide variety of applications. For example, light sources capable of reproducing the spectral characteristics of the sun are used in testing the weathering characteristics of various protective coatings, including the testing of paints, stains, exterior coatings, waxes, and the like. Further, solar simulators may be used in various medical research applications. For example, solar simulators are frequently used in research directed to skin cancer, photo-biological applications, photo toxicity, photo allergy testing, as well as various other medical applications. In addition, solar simulators are commonly used to determine the sun protection factor (hereinafter SPF) of various cosmetics, sun blocks, lotions, clothing, and the like. Typically, SPF testing examines erythemal response with and without a sun protection material applied to the skin of a mammal.
Presently, solar simulators commonly include high intensity lamps to provide an optical output to reproduce the spectral characteristics of the sun. While lamp-based solar simulator systems have proven somewhat useful in the past, a number of shortcomings have been identified. For example, often these systems require the use of optical filter systems to selectively tune the spectral output of the solar simulator to a desired wavelength range. These optical filter systems increase the cost and complexity of the solar simulator system. Further, numerous optical filters systems may be required to enable the solar simulator to output optical radiation in a variety of desired wavelength ranges. In addition, recent environmental regulations have severely limited or banned the use of some materials used in the manufacture of colored glass filters. As such, reproducing portions of the solar spectrum have become difficult if not impossible.
Thus, in light of the foregoing, there is an ongoing need for a solar simulator system capable of efficiently reproducing the solar spectrum. Moreover, ideally, the solar simulator would be capable of selectively reproducing portions of the solar spectrum.